1. Field of the Invention
The present invention relates to an optical transducer which can be connected to a rotary member for detecting the angular position thereof and generating corresponding electrical signals, comprising a support in which are mounted a light emitter and at least one light detector, and a shutter disc which can be connected to the rotary member and which is provided with a plurality of transparent radial elements which alternate with opaque radial elements capable of co-operating with the light emitter and light detctor for generation of the electrical signals.
2. Description of the Prior Art
A transducer is known, wherein the shutter disc is provided with a central hub. The disc and hub are housed with clearance within twocasing halves and, for precisely positioning the transducer with respect to the rotary member and in particular the shutter disc with respect to the light emitting and detecting elements, the arrangement has three separate positioning elements. A first element comprising an axial abutment which is fixed to the rotary member co-operates with the shutter disc to position it axially with respect to the rotary member; a second element which is provided directly on an outside wall of the casing axially positions same with respect to the rotary member; and a third element which is formed by a removable bush is used for radially positioning the casing with respect to the rotary member. While this known transducer has been found to be highly accurate and thus suitable for detecting even very small angular movements of the rotary member, it is fairly expensive both in regard to construction and assembly.